<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./js/vue.js"></script>
</head>

<body>
    <div class="app">
        <h2>{{count}}</h2>
        <button v-fk_click:click="countAdd">count++</button>
    </div>
    <script>
        Vue.directive('fk_click', function(el, binding){
            if (binding.arg === 'click') {
              el.onclick = (e)=> {
                vnode.context[binding.expression]()
              }
            }
          })
        const app = new Vue({
          el: '.app',
          data: {
            count:1
          },
          methods: {
            countAdd() {
              this.count++;
            },
          },
        })
    </script>
</body>

</html>